On Saturday, March 14, 2015 06:11:25 PM Ian Lepore wrote: > Author: ian > Date: Sat Mar 14 18:11:24 2015 > New Revision: 279997 > URL: https://svnweb.freebsd.org/changeset/base/279997 > > Log: > Use sbuf_new_for_sysctl() instead of plain sbuf_new() to ensure sysctl > string returned to userland is nulterminated. > > PR: 195668
This is not safe. sbuf_printf() is invoked with a lock held, so it isn't safe for the sbuf code to do a drain here. With sbuf_new_for_sysctl(), any call to an sbuf routine is a potential page fault, so the handler must either use sysctl_wire_old_buffer(), or the contents need to be output in one go. For this case I would prefer to use sbuf_len(sb) + 1 (or add INCLUDENUL to the args when creating it) and leave the sole SYSCTL_OUT() at the end. You will want to check the one or two other places you converted for this same issue as well. -- John Baldwin _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
